Ida Rothschild was last seen by her parents around 12:15 p.m. at the campground where the family is staying, according to Lt. Doug Pittman.

The father realized he hadn’t seen her after around 30 minutes and then searched for her for around an hour to a hour and a half with his wife before calling authorities for help, Pittman said.

Responders from around nine public agencies are on scene assisting with the search, along with more than 100 volunteers, Pittman said.

The county has also called in assistance from neighboring Bay Area counties to continue the search through the night and into Saturday if necessary.

So far, searchers have found no signs of Ida and no indications of foul play, Pittman said.

Pittman said the Rothschild family, which has two other children, boys aged 5 and 2, is visiting from Santa Fe, New Mexico. They spent Thursday in Muir Beach before coming to Samuel P. Taylor, a heavily forested state park west of Fairfax known for its redwoods and Lagunitas Creek.

Ida is described as being 4 feet 2 inches tall with very dark, almost black hair cut in blunt bangs. She was last seen wearing a pink floral-print terry cloth swimsuit coverup, Pittman said.

Pittman said searchers hope their efforts would be assisted by the full moon and clear skies.

The park and campground remained open Friday evening and no roads have been closed by the search, Pittman said.